William Lewis Reece, 61, was charged with first-degree murder and kidnapping in the 1997 killing of 19-year-old Tiffany Johnston, who was abducted from a car wash in Bethany, Oklahoma. Her body was found the next day in Canadian County.
SEE ALSO: Accused serial killer with ties to Houston found guilty in Oklahoma teen's kidnapping and murder
On Wednesday, a jury in Oklahoma remanded the death penalty for Reece. He will be formally sentenced to death in August.
"This was for Tiff. Even though it will help families in Texas, this was Tiffany's time," said Tiffany's mom, Kathy Dobry.
A Texas Ranger testified during a preliminary hearing in 2017 that Reece acknowledged killing "the Oklahoma girl" during an interview in March 2016. He's also suspected of killing a woman and two girls in Texas in 1997.
Johnston, 20-year-old Kelli Cox, 17-year-old Jessica Cain and 12-year-old Laura Smither all disappeared over a four-month period in 1997, after Reece had been released from an Oklahoma prison for previous rape and kidnapping convictions. Smither was from Friendswood and Cain was from Tiki Island. Cox was from Denton, Texas.
In 2016, Reece was already serving a 60-year prison sentence in Texas for kidnapping when he led police to graves in southeast Houston and Brazoria County where Cain and Cox's remains were found. In the end, investigators said he confessed to the four murders and cooperated as part of a deal with prosecutors who agreed to take the death penalty off the table in Texas.
Meanwhile, Reece still faces murder charges in Galveston County for the deaths of Cain and Laura Smither, and it's unclear how those will move forward.
WATCH: Mom of girl killed says she felt 'relief' after guilty verdict
On Friday, the father of Cain, C.H. Cain, issued the following statement after Reece was found guilty:
"I'm just glad that he can never harm another innocent young woman. We will miss Jessica every day of our lives, but as for Reece, my heart had been at ease for a very long time, because I know that the final judgement belongs to God. What happens on Earth is temporary. What God decides is eternal."
SEE ALSO: Remembering Jessica Cain, 20 years after her disappearance
EXCLUSIVE: Woman says she was kidnapped by William Reece speaks out for first time
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